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How can you use the prime factorization of two numbers to find the LCM?
Wiki User
∙ 7y ago
You can use the numbers in common in the prime factorization to find the LCM (least common multiple of two numbers). Multiply all the prime factors together, but if the two numbers have a prime factor in common, only use that number once. Here are a few examples:
Find the LCM of 40 and 35:
The prime factorization of 40 is 2*2*2*5.
The prime factorization of 35 is 5*7.
The prime factorization both have a 5 in common, so you only need one five. The LCM then is 2*2*2*7*5 = 280.
Find the LCM of 24 and 20:
24 = 2*2*2*3.
20 = 2*2*5.
The prime factorization have two twos in common, so you only need one two from each pair. You will still need another 2 since the third 2 in the prime factorization of 24 does not have a pair in the factorization of 20.
The LCM then is 2*2*2*3*5 = 120.
Find the LCM of 15 and 4:
15 = 3*5
4 = 2*2
There are no matching pairs between the prime factorization, so find the LCM by multiplying all the numbers together:
2*2*3*5=60
Find the LCM of 60 and 100:
140 = 2*2*3*5
100 = 2*2*5*5
There are two pairs of 2s and a pair of 5. You can think of it like this:
140 = (2*2*5)*3
100 = (2*2*5)*5
The numbers in parentheses are pairs so you only need one of them. In this case, the LCM is (2*2*5)*3*5 = 300.
Wiki User
∙ 7y ago
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How do you find the prime factorization of 18 and 21?
Draw the prime factorization table and put both the numbers on it. Find common prime factors and divide both of them writing the products down. Do this until the quotients are either 1 or any prime number. Write down all the factors used and it will be the prime factorization. Multiply them and you will find the LCM of the numbers. Here, 18,21 6,7...................(/3) Prime factorization=6*7*3 LCM=42*3=126
What is the LCM of 3 and 17 using prime factorization?
3 and 17 are both prime. Any time you have prime numbers, you multiply them together to get the LCM.
Is prime factorization always useful in finding LCM?
Most of the time. If you can recognize that the two numbers are relatively prime, factorization isn't necessary. Just multiply the two numbers together.
Where do you use prime factorization in real life?
In finding the LCM or HCF of two or more numbers
How do you find the lcm of three numbers when all of them are prime?
When all of them are prime numbers,then just multiply the numbers to get the LCM of those 3 numbers.
How do you find the LCM of 16 63 and 75 using prime factorization?
The LCM of the given three numbers using prime factorization is 25200
What is the LCM of 3x3x3x2x2x2x2?
You have written the prime factorization for 432. You need at least two numbers to find an LCM.
What method would you useto find he LCM of a group of four numbers?
Prime factorization.
What is the LCM of 50 using prime factorization?
You need at least two numbers to find an LCM no matter what you use.
How are gcf LCM and prime factorization related?
You can find the GCF and/or the LCM of a set of numbers by comparing the prime factorizations of the individual members of the set.
What is the LCM of 25 using prime factorization?
You need at least two numbers to find an LCM no matter what method you choose.
What is the prime factorization to find the LCM of 4?
The prime factorization of 4 is 2 x 2. It is not possible to find the LCM of a single number.
How do you find the prime factorization of 18 and 21?
Draw the prime factorization table and put both the numbers on it. Find common prime factors and divide both of them writing the products down. Do this until the quotients are either 1 or any prime number. Write down all the factors used and it will be the prime factorization. Multiply them and you will find the LCM of the numbers. Here, 18,21 6,7...................(/3) Prime factorization=6*7*3 LCM=42*3=126
What is The LCM of 126 using prime factorization?
You need at least two numbers to find an LCM.
What is the LCM of 20 using prime factorization?
It doesn't matter which method you use. You still need at least two numbers to find an LCM. There is no LCM of 20.
What is the prime factorization with Lcm of 20 and 37?
The LCM of these numbers is 740. LCM is Least Common Multiple.
What is the least common multiple of 28 using prime factorization?
You need at least two numbers to find an LCM.
